This invention deals with a side shield retention clamp for eyeglasses.
Side shields can be mounted to the temples of safety eyeglass frames to help shield the wearer from dangerous materials that could enter the eye in a particular work environment. In fact, employers often provide employees working in such environments with their own personal prescription eyeglasses having side shields at no cost in order to safeguard their workers"" health and productivity. Unfortunately, many workers are tempted to remove the side shields when not in the workplace in order to make their eyeglasses appear more stylish or appealing. This leads to the loss of the side shields provided and often leads to the worker attempting jobs where safety requires the presence of such side shields without the shields being present.
In order to prevent the removal and loss of side shields, employers and manufacturing facilities have sought means for permanently affixing side shields to the temples of the eyeglasses provided to their employees. Mechanical locking means (such as rivets, screws, and lock nuts) as well as adhesives have been used for this purpose. Representative examples of prior art attempts to solve this problem using mechanical locking means can be seen in the following U.S. patents:
U.S. Pat. No. 5,548,351 issued to Hirschman et al. in 1996 for a xe2x80x9cMethod and Kit for Attaching Side Shields to Eyeglass Temples.xe2x80x9d
U.S. Pat. No. 5,748,278 issued to Simmons, Sr. in 1998 for a xe2x80x9cEyeglass Shield for Removable Attachment to Eyeglass Lens Frames.xe2x80x9d
U.S. Pat. No. 5,798,815 issued to Hirschman et al. in 1998 for a xe2x80x9cMethod and Kit for Attaching Side Shields to Eyeglass Temples.xe2x80x9d
U.S. Pat. No. 6,007,196 issued to Saba et al. in 1999 for a xe2x80x9cRetainer for Eyeglass Frames having Sideshields.xe2x80x9d
Most of the foregoing patents deal with systems that require a specialized eyeglass shield for their use. Saba et al. describe an eyeglass shield attachment mechanism that is intended for use with a common slide-on shield. Such shields are placed in position by sliding them into place on the temple adjacent the lens frame. They can be removed by reversing this process and sliding them back from their position. They can also be removed by separating the temple from the eyeglass frame and sliding the shield forward. Thus, some mechanism must be provided to block them from sliding forward or back from the end of the temple adjacent the lens frame. Saba et al. provide a hook with a lip that fastens into an appropriately shaped side opening in the eyeglass shield. This hook is at one end of an arm with the other end attached to a clamp that can be tightened onto the temple behind the shield after the shield is in position. While this method can provide some benefits, it is far from perfect. For example, the apparatus of Saba et al. is subject to easy removal by rotating the side shield around the axis formed by the temple of the glassesxe2x80x94i.e.xe2x80x94it remains easy to remove by twisting. Thus, there remains a need for efficient and effective mechanical means for securely affixing common slide-on side shields to the temples of eyeglasses.
Overall, my invention can be summarized as a temple clamp having an arm extending therefrom with a hole rather than a hook at the end of this arm. A screw extends through the hole, but is not tapped into the hole. Instead, in my preferred embodiments, I use a sliding fastener comprised of a shield clamping nut arranged on a projection that extends along an outside face of the temple. The nut extends into a hole in the side shield from the inside of the shield and has interior threads. The screw is threaded through these to be jammed against the temple. The projection has a flat face that fits against the outside of the temple, extends into the clamp slot, and is clamped against the temple when the clamp is tightened (via a clamp screw). Only the screw projecting through the shield clamping nut against the temple engages the temple, as the clamp screw passes under the temple and engages the opposing side of the clamp directly. Thus, my invention uses an arm attached to a clamp to hold a screw that receives a nut to hold a side shield in position. In the preferred embodiment, both the screw and the nut extend through the side shield. The nut and its projection are on the inside of the shield and the arm from the clamp is on the outside of the shield so that these parts straddle the shield, with at least a portion of the nut extending into the hole in the side shield.
This arrangement provides a strong and non-twistable clamp firmly engaging both sides of the temple and also a strong engagement with the shield by disposing a nut and screw that extend directly through a hole in the shield and are also clamped to the temple. The result is generally more complex than prior art devices since two screws are involved, but it is also much more secure than these devices.